1.a worker pulls horizontally on a crate across a rough horizontal surface, causing it to move forward with constant velocity. force a is the force exerted by the worker and force b is the force of friction due to the surface. what is the relationship between a and b?

a = b

a< b

a > b

2. in a color picture tube, an electric field exerts a net force of magnitude 1.60 × 10-13 n on an electron. the rest mass of an electron is 9.11 × 10-31 kg. what is the electron's accceleration?

1.76 × 1017 m/s2

1.96 × 1024 m/s2

1.45 × 1043 m/s2

1.60 × 10-13 m/s2

1.

The relationship between Force A and Force B is given as:

A = B

Explanation:

To produce acceleration to a body, an unbalanced force must be applied. Meaning that a Force must be applied to the body greater than that of Force of Friction.

In our case, a Force A is exerted on the crate which is moving with a constant velocity. As there is no acceleration, the force applied must be equal to the force of Friction B.

2.

The electron's acceleration is 1.756 x 10¹⁷ ms⁻².

Explanation:

Electric field exerts a Force on the electron given as:

F = 1.6 x 10⁻¹³ N

Rest mass of electron = 9.11 x 10⁻³¹ kg

According to newton's 2nd law of motion, a net force F applied on the electron must produce an acceleration 'a' which is directly proportional to the Force and inversely proportional to the rest mass of the electron given as:

a = F/m

a = (1.6 x 10⁻¹³)/(9.11 x 10⁻³¹)

a = 1.756 x 10¹⁷ ms⁻²

initial speed when it is dropped is 150 ft/s

now at the same moment the acceleration due to gravity is perpendicular to its velocity

so as we know that

now we have centripetal acceleration a = 32 ft/s^2 as its perpendicular to velocity

while tangential acceleration at the same moment will be zero

so

now radius of curvature is given as

so the radius of curvature just after it is dropped is 703.125 ft