Physics Answers

How can a rocket change direction when it is far out in space and esentially in a vacuum?

When you release an inflated but untied balloon, why does it fly across the room?

We claim that momentum is conserved, yet most moving objects eventually slow down and stop. Explain.

A 1000 kg Civic is travelling at 30 m/s and accelerates to 40 m/s in 10 seconds.
a. What is the change in momentum?
b. What is the impulse?
c. What is the net force that causes the change?

A 1000 kg Civic is travelling at 30 m/s and accelerates to 40 m/s in 10 seconds.
a. What is the momentum of the car before accelerating?
b. What is the momentum of the car after accelerating for 10 seconds?

Three particles are situated in 3-D space. The position of each particle is represented by the following vectors:
• A 5-kg particle at r1 = 4i + 3j + 5k
• A 3-kg particle at r2 = –3i + 5j + 3k
• A 6-kg particle at r3 = 5i – 6k
a. How far is each particle from the center of mass.

A 1200-kg station wagon is moving along a straight highway at 12.0 m/s. Another car, with mass 1800-kg and speed 20.0 m/s, has its center of mass 40.0 m ahead at the center of mass of the station wagon. Find the position of the center of mass of the system consisting two automobiles.

A 4-kg mass is at the origin and a 2-kg mass is at x=6 cm. Find the center of mass (x).

Two spherical objects have masses of 1.5 x 10^5 kg and 8.5 x 10^2 kg. Their centers are separated by a distance of 2500 m. Find the gravitational attraction between them

The plates of parallel capacitor 5.0×10-³m apart maintained at a potential difference of 5.0×10^4. Calculate the magnitude of the a. Electric field intensity between the plates b. Force of the electron c. Acceleration if the electron ( electron charge =1.60×10^-19c)