Answer:
The correct answer is "4.443 sec".
Explanation:
Given:
Mass of child,
= 34 kg
Mass of swing,
= 18 kg
Length,
= 4.9 m
The time period of pendulum will be:
T = 
= 
=
Answer:
The speed of the car, v = 19.997 m/s
Explanation:
Given,
The centripetal acceleration of the car, a = 13.33 m/s²
The radius of the curve, r = 30 m
The centripetal force acting on the car is given by the formula
F = mv²/r
Where v²/r is the acceleration component of the force
a = v²/r
Substituting the values in the above equation
13.33 = v²/30
v² = 13.33 x 30
v² = 399.9
v = 19.997 m/s
Hence, the speed of the car, v = 19.997 m/s
Answer:
He needs 1.53 seconds to stop the car.
Explanation:
Let the mass of the car is 1500 kg
Speed of the car, v = 20.5 m/s
He will not push the car with a force greater than, 
The impulse delivered to the object is given by the change in momentum as :

So, he needs 1.53 seconds to stop the car. Hence, this is the required solution.
Answer:
50%
Explanation:
Humidity is the amount water vapor present in the atmosphere.
Relative humidity is defined as the ratio of partial water vapor present in air to the actual water vapor at a particular temperature. It is expressed in percentage and the higher the percentage RH, the more the saturated water vapor present in the atmosphere and vice versa.
It is expressed mathematically as shown;
RH = actual water vapor in air/saturated water vapor × 100%
If the actual water vapor in the air was 4 grams per cubic meter and the air's capacity to hold water vapor was 8 grams per cubic meter
Actual water vapor = 4g/cm³
Air's water capacity (saturated water vapor) = 8g/cm³
RH = 4/8×100
RH = 50%