Other Physics Answers

Question No. 1

The driver of a 2.0 × 103 kg red car traveling on the highway at 45m/s slams on his brakes to avoid striking a second yellow car in front of him, which had come to rest because of blocking ahead as shown in above Fig. After the brakes are applied, a constant friction force of 7.5 × 103 N acts on the car. Ignore air resistance.

(a) Determine the least distance should the brakes be applied to avoid a collision with the other vehicle?

(b) If the distance between the vehicles is initially only 40.0 m, at what speed would the collision occur?

(c) Write your conclusive observations on the result obtained from this numerical. i.e. the importance of Physics in daily life.

The following data were collected during a short race between

two friends.

Velocity (m/s) 0 0.5 1 1.5 2 2 4 6 2 0

Time (s) 0 2 4 6 8 10 12 14 16 18

a) Describe the different sections of the graph.

b) Determine the acceleration over the first eight seconds.

c) Determine the maximum acceleration.

d) Using the graph calculate the displacement:

i) over the first eight seconds

ii) the total race.

e) Find the maximum velocity reached by the runner.

What is the acceleration of a 50 kg object pushed with a force of 500 newtons?

A 50 kg skater pushed by a friend accelerates 5 m/s2 . How much force did the friend apply

A 300kg block start at rest from the top of 30° incline and accelerate uniformly down the incline ,moving 20m in 1.50s. (a)Find the magnitude of the acceleration of the block .(b)find the coefficient of friction between the block and the incline .(c)Find the magnitude of the frictional force acting on the block.(d)Find the speed of the block after it has slide a distance of2.00m.[g=9.8ms squared]

b) A matter has a body-centered cubic unit cell with a length of 330 pm along an edge

and a density of 8.57 g cm^-3. Calculate the atomic mass of the matter.

c) Find the total energy of a moving object of mass 6.3 kg and momentum 11.5 x 10 kgms^-1

5. c) Find the total energy of a moving object of mass 6.3 kg and momentum 11.5 x 10 kgms^-1

5. b) A matter has a body-centered cubic unit cell with a length of 330 pm along an edge

and a density of 8.57 g cm^-3. Calculate the atomic mass of the matter.

4. c) If 12N force is applied t a fluid of cross-section 5.34 cm² with a shearing rate of 0.7s then find the viscosity of the fluid.

3. c) A wire of length 7 m and radius 2.37 mm is stretched by a load of 12370 gm and increased by 1.78% of the original length. Find the stress, strain, and Young's modulus of the material of the wire.