Questions from Modern Physics

Q: A skier starts at the top of a very large, frictionless

A skier starts at the top of a very large, frictionless snowball, with a very small initial speed, and skis straight down the side (Fig. P7.55). At what point does she lose contact with the snowball a...

Q: A ball is thrown upward with an initial velocity of 15 m

A ball is thrown upward with an initial velocity of 15 m/s at an angle of 60.0° above the horizontal. Use energy conservation to find the ball’s greatest height above the ground.

Q: In a truck-loading station at a post office, a

In a truck-loading station at a post office, a small 0.200-kg package is released from rest at point A on a track that is one quarter of a circle with radius 1.60 m (Fig. P7.57). The size of the packa...

Q: A truck with mass m has a brake failure while going down

A truck with mass m has a brake failure while going down an icy mountain road of constant downward slope angle a (Fig. P7.58). Initially the truck is moving downhill at speed v0. After careening downh...

Q: A certain spring found not to obey Hooke’s law exerts a restoring

A certain spring found not to obey Hooke’s law exerts a restoring force Fx(x)= -ax - bx2 if it is stretched or compressed, where a = 60.0 N/m and b = 18.0 N/m2. The mass of the spring is negligible. (...

Q: A sled with rider having a combined mass of 125 kg travels

A sled with rider having a combined mass of 125 kg travels over a perfectly smooth icy hill (Fig. P7.60). How far does the sled land from the foot of the cliff? Fig. P7.60:

Q: A conservative force F is in the +x-direction and

A conservative force F is in the +x-direction and has magnitude F(x)= a/(x + x0)2, where a = 0.800 N#m2 and x0 = 0.200 m. (a) What is the potential-energy function U1x2 for this force? Let U(x) → 0 as...

Q: A 2.50-kg block on a horizontal floor is

A 2.50-kg block on a horizontal floor is attached to a horizontal spring that is initially compressed 0.0300 m. The spring has force constant 840 N/m. The coefficient of kinetic friction between the f...

Q: A 3.00-kg block is connected to two ideal

A 3.00-kg block is connected to two ideal horizontal springs having force constants k1 = 25.0 N/cm and k2 = 20.0 N/cm (Fig. P7.62). The system is initially in equilibrium on a horizontal, frictionless...

Q: A 0.150-kg block of ice is placed against

A 0.150-kg block of ice is placed against a horizontal, compressed spring mounted on a horizontal tabletop that is 1.20 m above the floor. The spring has force constant 1900 N>m and is initially compr...