For horizontal range of a projectile \(\displaystyle{R}={{V}_{{{0}}}^{{{2}}}}\frac{{\sin{{20}}}}{{g}}\) Hence \(\displaystyle{V}{0}=\sqrt{{{R}\cdot\frac{{g}}{{\sin{{20}}}}}}=\sqrt{{{183}\cdot\frac{{9.8}}{{\sin{{60}}}}}}={45.5}\frac{{m}}{{s}}\)

asked 2021-02-19

A 10 kg objectexperiences a horizontal force which causes it to accelerate at 5 \(\displaystyle\frac{{m}}{{s}^{{2}}}\), moving it a distance of 20 m, horizontally.How much work is done by the force?

A ball is connected to a rope and swung around in uniform circular motion.The tension in the rope is measured at 10 N and the radius of thecircle is 1 m. How much work is done in one revolution around the circle?

A 10 kg weight issuspended in the air by a strong cable. How much work is done, perunit time, in suspending the weight?

A 5 kg block is moved up a 30 degree incline by a force of 50 N, parallel to the incline. The coefficient of kinetic friction between the block and the incline is .25. How much work is done by the 50 N force in moving the block a distance of 10 meters? What is the total workdone on the block over the same distance?

What is the kinetic energy of a 2 kg ball that travels a distance of 50 metersin 5 seconds?

A ball is thrown vertically with a velocity of 25 m/s. How high does it go? What is its velocity when it reaches a height of 25 m?

A ball with enough speed can complete a vertical loop. With what speed must the ballenter the loop to complete a 2 m loop? (Keep in mind that the velocity of the ball is not constant throughout the loop).

A ball is connected to a rope and swung around in uniform circular motion.The tension in the rope is measured at 10 N and the radius of thecircle is 1 m. How much work is done in one revolution around the circle?

A 10 kg weight issuspended in the air by a strong cable. How much work is done, perunit time, in suspending the weight?

A 5 kg block is moved up a 30 degree incline by a force of 50 N, parallel to the incline. The coefficient of kinetic friction between the block and the incline is .25. How much work is done by the 50 N force in moving the block a distance of 10 meters? What is the total workdone on the block over the same distance?

What is the kinetic energy of a 2 kg ball that travels a distance of 50 metersin 5 seconds?

A ball is thrown vertically with a velocity of 25 m/s. How high does it go? What is its velocity when it reaches a height of 25 m?

A ball with enough speed can complete a vertical loop. With what speed must the ballenter the loop to complete a 2 m loop? (Keep in mind that the velocity of the ball is not constant throughout the loop).

asked 2021-05-16

Look Out! A snowball rolls off a barn roof that slopes downward at an angle of 40 degrees . The edge of the roof is 14.0 m above the ground, and the snowball has a speed of 7.00 m/s as it rolls off the roof. Ignore air resistance.

A man 1.9 m tall is standing 4.0 m from the edge of the barn. Will he be hit by the snowball?

A man 1.9 m tall is standing 4.0 m from the edge of the barn. Will he be hit by the snowball?

asked 2021-03-22

A box is sliding with a speed of 4.50 m/s on a horizontal surface when, at point P, it encounters a rough section. On the rough section, the coefficient of friction is not constant but starts at .100 at P and increases linerly with distance past P, reaching a value of .600 at 12.5 m past point P. (a) Use the work energy theorem to find how far this box slides before stopping. (b) What is the coefficient of friction at the stopping point? (c) How far would the box have slid iff the friciton coefficient didn't increase, but instead had the constant value of .1?

asked 2021-02-10

An electron enters a uniform magnetic field B= 0.23T at a 45 degree angle to B. Determine the pitch p (distance between loops) of the electron's helical path assuming its speed to be \(\displaystyle{3.0}\cdot{10}^{{6}}\) m/s.

asked 2021-05-18

A rifle that shoots bullets at 460 m/s is to be aimed at atarget 45.7 m away. if center of the target is level with therifle, how high above the target must the rifle barrel be pointedso that the bullet hits the dead center?

asked 2021-02-22

A truck engine transmits 28 kW (27.5 hp) to the driving wheels when the truck is traveling at a constant velocity of magnitude 60 km/h (37.3 m/h) on a level road. (a) What is the resisting force acting on the truck? (b) Assume that 65% of the resisting force is due to rolling friction and that the remainder is due to air resistance. If the force of rolling friction is independent of speed and the force of air resistance is proportional to the square of speed, what power will drive the truck at 30 km/h? at 120 km/h? give your answers in kilowatts and in horsepower.

asked 2021-02-21

How do you solve this problem? I don' t even know whereto begin.

A Ferrari with a mass of 1400 kg approaches a freeway underpassthat is 10 m across. At what speed must the car be moving, inorder for it to have a wavelength such that it might somehow"diffract" after passing through this "single slit"? How dothese conditions compare to normal freeway speeds of 30m/s?

A Ferrari with a mass of 1400 kg approaches a freeway underpassthat is 10 m across. At what speed must the car be moving, inorder for it to have a wavelength such that it might somehow"diffract" after passing through this "single slit"? How dothese conditions compare to normal freeway speeds of 30m/s?

asked 2021-04-16

A child is playing on the floor of a recreational vehicle (RV) asit moves along the highway at a constant velocity. He has atoy cannon, which shoots a marble at a fixed angle and speed withrespect to the floor. The cannon can be aimed toward thefront or the rear of the RV. Is the range toward the frontthe same as, less than, or greater than the range toward the rear?Answer this question (a) from the child's point of view and (b)from the point of view of an observer standing still on the ground.Justify your answers.

asked 2021-04-14

A medical technician is trying to determine what percentage of apatient's artery is blocked by plaque. To do this, she measures theblood pressure just before the region of blockage and finds that itis \(\displaystyle{1.20}\times{10}^{{{4}}}{P}{a}\), while in the region of blockage it is \(\displaystyle{1.15}\times{10}^{{{4}}}{P}{a}\). Furthermore, she knows that blood flowingthrough the normal artery just before the point of blockage istraveling at 30.0 cm/s, and the specific gravity of this patient'sblood is 1.06. What percentage of the cross-sectional area of thepatient's artery is blocked by the plaque?

asked 2021-04-15

A person stands in a stationary canoe and throws a 5.22 kgstone with a velocity of 8.20 m/s at an angle of 34.0 degrees abovethe horizontal. The person and the canoe have a combined massof 105 kg. Ignoring air resistance and effects of the water,find the horizontal recoil velocity (magnitude and direction) of the canoe.