Answer:
b
Explanation:
When an object is in circular motion, the direction of velocity is in the direction of tangent to the circle and acceleration is always directed towards the radial direction. This means that velocity is always perpendicular to acceleration of the object.
Hence option (b)-The velocity and acceleration vectors are perpendicular is correct.
<h2>The K.E of the charge is 1.02 x 10⁻¹⁷ J</h2>
Explanation:
When the charge of 2e is placed in between the plates .
The force applied on this charge by plates is = q E
here q is the magnitude of charge = 2 e = 2 x 1.6 x 10⁻¹⁹ C
and E is the magnitude of electric field intensity
The work done = Force x displacement
Thus W = q E x S
here S is displacement
Therefore W = 2 x 1.6 x 10⁻¹⁹ x 4 x 8
= 1.02 x 10⁻¹⁷ J
This work will be converted into the kinetic energy of charge .
Thus K.E = 1.02 x 10⁻¹⁷ J
The rock would be at a point 12 m from water at a time <u>4.8 s</u>.
Take the origin of the coordinate system at the top of the cliff. It is thrown upwards with a velocity u. When the rock is at a point 12 m from water, calculate the vertical displacement of the rock from the origin.

Use the equation of motion,

The rock falls under the acceleration due to gravity, directed down wards.
Substitute 18 m/s for u, -26 m for y and -9.8 m/s² for a=g.

Solve the quadratic equation for t.

Taking only the positive value,

After a time of <u>4.8 s</u> the rock would be at a distance of 12 m from water.
Answer:
A. A sea wave generated by a displacement of water
Explanation:
Answer:
d. at the same velocity
Explanation:
I will assume the car is also travelling westward because it was stated that the helicopter was moving above the car. In that case, it depends where the observer is. If the observer is in the car, the helicopter would look like it is standing still ( because both objects have the same velocity). If the observer is on the side of the road, both objects would be travelling at the same velocity. Also recall that, velocity is a vector quantity; it is direction-aware. Velocity is the rate at which the position changes but speed is the rate at which object covers distance and it is not direction wise. Hence velocity is the best option.