Answer:
I. Speed = 20m/s
II. Velocity = 20m/s due North.
Explanation:
<u>Given the following data;</u>
Distance = 40m
Time = 2secs
To find the speed;
Mathematically, speed is given by the formula;
Substituting into the equation, we have;
<em>Speed = 20m/s.</em>
In physics, we use the same formula for calculating speed and velocity. The only difference is that speed is a scalar quantity and as such has magnitude but no direction while velocity is a vector quantity and as such it has both magnitude and direction.
<em>Therefore, the velocity is 20m/s due North</em>.
Density is the mass per unit volume of any object. It is calculated by dividing the mass of an object by its volume. This is:
ρ = m/V
ρ = 4.05 g / 12 mL
ρ = 0.3375 g/mL
<h3>
ρ ≅ 0.338 g/mL</h3>
OPTION A
when the ball hits the floor and bounces back the momentum of the ball changes.
the rate of change of momentum is the force exerted by the floor on it.
the equation for the force exerted is
f = rate of change of momentum
v is the final velocity which is - 3.85 m/s
u is initial velocity - 4.23 m/s
m = 0.622 kg
time is the impact time of the ball in contact with the floor - 0.0266 s
substituting the values
since the ball is going down, we take that as negative and ball going upwards as positive.
f = 189 N
the force exerted from the floor is 189 N