Physics Answers

A 3.5kg block is pushed along a horizontal floor by a force F of magnitude 15N at an angle 40°W horizontal. The coefficient of kinetic friction between the block and the floor is 0.25. Calculate the magnitude of:

(a) frictional force on the block from the floor

(b) the block's acceleration

3. A small sphere of charge +6 x 10-⁶C is suspended by a string of negligible mass. A charge of -9 x 10^-6 C is placed directly to the right of the sphere and 0.22m away from it. The string is deflected 5° from the vertical. Find the tension in the string.

A drum rotates around its central axis at an angular velocity of 12.60 rad/s. If the drum then slows at a constant rate of 4.20 rad/s2.

(a) how much time does it take?

(b) through what angle does it rotate in coming to rest (3.0s , 18.9 rad)

If you have a mass of 55 kg and you are standing 3 meters away from your car, which has a mass of 1234 kg, how strong is the force of gravity between you and the car?

With its engine cut off, a small airplane glides downward at an angle of 15° below the 

horizontal at a speed of 240 km/h. (a) What are the horizontal and the vertical 

components of its velocity? (b) If the airplane is initially at a height of 2000 m above the 

ground, how long does it take to crash into the ground?  

Note: For (a), you may use m/s or km/h as long as you indicate, and you are consistent 

with the unit that you use. For (b) you may use seconds(s) or minute(m), just indicate the 

unit used.

In an electrolysis experimenta cathode of mass 5g found to weight 5.01g after a current of 5A flows for 50 second. What is electrochemical equivalent of the deposited substance ?

Which of the following activities would lead to the creation of magnetic fields?

a. Placing a proton in an environment where it is completely at rest

b. Placing the nucleus of an atom in an environment where it is

moving at constant velocity

c. Placing the nucleus of an atom in an environment where it has

zero acceleration and a zero velocity d. Placing a negative ion in an environment where it has a nonzero

acceleration that is constantly changing

e. Placing an electron in an environment where it is moving at 80 m/s around a circular path

Object A and Object B are charged with +37.2 u coulombs and -68.1 μ coulombs, respectively Given Chat the wo objects are separated by 0.37 m. Which of the following statements is/are valid?

a. Object A attracts object B with a force of 20.5 N

b. Object 8 repels object A with a force of 166.4 N

c. Object A repels object B with a force of 166.4 N d. Object B attracts object A with a force of 166.4 N

e. Object B attracts object A with a force of 2015 N

f. Object A repels object 8 with a force of 20.5 N

g. Object B repels object A with a force of 20.5 N

HObject A attracts object 8 with a force of 166.4 N

Which of the following activities would lead to the creation of magnetic fields?

a. Placing a positive ion in an environment where it has zero acceleration and a zero velocity

b. Placing a proton in an environment where it is moving at 2 m/s in a straight line

c. Placing a positive ion in an environment where it is completely at rest d. Placing the nucleus of an atom in an environment where it has zero acceleration and a nonzero velocity

e. Placing an electron in an environment where it has a nonzero acceleration that is constantly changing

Which of the following activities would lead to the creation of independent magnetic fields (ie. One that does not depend on any electric field in its proximity) ?

a. Placing a proton in an environment where its velocity constantly changing

b. Placing a positive ion in an environment where it is moving at 8

m/s around a circular path

c. Placing a negative ion in an environment where it is moving at

constant velocity d. Placing an electron in an environment where it has zero

acceleration and a zero velocity

e. Placing an electron in an environment where it is completely at

rest