Answer:
B
Explanation:
Laboratories are usually controlled: however, in public places, there are way too many factors that could change an experiment
Answer:
B. When the racket hits the tennis ball with a force, the tennis ball applies an equal but opposite force to the racket.
Explanation:
According to the Newton's third law of motion every action has equal and opposite reaction. So, when the force is applied by the racket on the ball then the ball also applies an equal intensity of force in the opposite direction on the racket. It is just that the the force on the racket is absorbed by the player holding it.
Answer:
Frictional Force: Frictional force is the force caused by the relative motion of two surfaces that come into contact with each other.
Increasing the number of bulbs in a series circuit decreases the brightness of the bulbs. In a series circuit, the voltage is equally distributed among all of the bulbs. Bulbs in parallel are brighter than bulbs in series. In a parallel circuit the voltage for each bulb is the same as the voltage in the circuit.
Answer:
1.) U = 39.2 m/s
2.) t = 4s
Explanation: Given that the
height H = 78.4m
The projectile is fired vertically upwards under the acceleration due to gravity g = 9.8 m/s^2
Let's assume that the maximum height = 78.4m. And at maximum height, final velocity V = 0
Velocity of projections can be achieved by using the formula
V^2 = U^2 - 2gH
g will be negative as the object is moving against the gravity
0 = U^2 - 2 × 9.8 × 78.4
U^2 = 1536.64
U = sqrt( 1536.64 )
U = 39.2 m/s
The time it takes to reach its highest point can be calculated by using the formula;
V = U - gt
Where V = 0
Substitute U and t into the formula
0 = 39.2 - 9.8 × t
9.8t = 39.2
t = 39.2/9.8
t = 4 seconds.
