A rock is dropped from rest from a height h above the ground. It falls and hits the ground with a speed of 11 m/s. From what height should the rock be dropped so that its speed on hitting the ground is 22 m/s? Neglect air resistance.

The engine in an imaginary sports car can provide constant power to the wheels over a range of speeds from 0 to 120 kilometers per hour (km/h). At full power, the car can accelerate from zero to 50.0 km/h in time 1.50 s. At full power, how long would it take for the car to accelerate from 0-100km/h? Neglect friction and air resistance.               Needs Complete typed solution with 100 % accuracy.

A 55 kg skier starts from rest at the top of a ski jump, point ? shown in the figure, and travels down the ramp. If friction and air resistance can be neglected, determine (a) her speed ?? when she reaches the horizontal end of the ramp at ?, and (b) the distance ? to where she strikes the ground at ?.

The drawing shows a skateboarder moving at 6.80 m/s along a horizontal section of a track that is slanted upward by 0 = 41.0° above the horizontal at its end, which is 0.780 m above the ground. When she leaves the track, she follows the characteristic path of projectile motion. Ignoring friction and air resistance, find the maximum height H to which she rises above the end of the track. 6.80m/s 0.780m

1.A sled slides without friction down a small, ice-coveredhill. If the sled starts from rest at the top of the hill, its speed atthe bottom is 7.50 m/s. (a) On a second run, the sled starts witha speed of 1.50 m/s at the top. When it reaches the bottom ofthe hill, is its speed 9.00 m/s, more than 9.00 m/s, or less than9.00 m/s? Explain. (b) Find the speed of the sled at the bottomof the hill after the second run. Draw and Explain.

You cast a pebble at 2.4 m/s at a pond from 0.8 m above ground. How fast is it when it is about to land in the pond .5 m below the ground? Hint: use mechanical energy conservation. The direction of the velocity is irrelevant. It doesn't have to travel straight up or down. Pebble's final position is negative.

You drop a 2.20 kg book to a friend who stands on the ground at distance D = 15.0 m below. Your friend's outstretched hands are at distance d = 1.30 m above the ground (see the figure). (a) What is the speed of the book when it reaches her hands? (b) If we substituted a second book with twice the mass, what would its speed be when it reaches her hands? (c) If, instead, the book were thrown down with initial speed 6.80 m/s, what would be the answer to (a)? (a) Number i Units (b) Number i Units (c) Number i Units

The drawing shows a skateboarder moving at 6.70 m/s along a horizontal section of a track that is slanted upward by 0 = 48.0° above the horizontal at its end, which is 0.530 m above the ground. When she leaves the track, she follows the characteristic path of projectile motion. Ignoring friction and air resistance, find the maximum height H to which she rises above the end of the track. 6.70m/s 0.530m

A proton (mass m = 1.67 × 10-27 kg) is being accelerated along a straight line at 9.80 × 1011 m/s2 in a machine. If the proton has an initial speed of 8.20 × 105 m/s and travels 5.90 cm, what then is (a) its speed and (b) the increase in its kinetic energy?

I need help with this physics question #2