Answer:
54 km/hr
Explanation:
m/s to km/hr => 18/5
15 m/s to km/hr => 15 x 18/5 =>3 x 18 => 54km/hr
Answer:

Explanation:
Work is equal to the product of force and distance.

The force is 8 Newtons and the distance is 15 meters.

Substitute the values into the formula.

Multiply.

- 1 Newton meter is equal to 1 Joule
- Our answer of 120 N*m equals 120 J

The work done is <u>120 Joules</u>
The crate’s acceleration is gravity= 9.81m/s^2
The ball’s acceleration is also gravity=9.81m/s^2
Answer:
Explanation:
potential energy of compressed spring
= 1/2 k d²
= 1/2 x 730 d²
= 365 d²
This energy will be given to block of mass of 1.2 kg in the form of kinetic energy .
Kinetic energy after crossing the rough patch
= 1/2 x 1.2 x 2.3²
= 3.174 J
Loss of energy
= 365 d² - 3.174
This loss is due to negative work done by frictional force
work done by friction = friction force x width of patch
= μmg d , μ = coefficient of friction , m is mass of block , d is width of patch
= .44 x 1.2 x 9.8 x .05
= .2587 J
365 d² - 3.174 = .2587
365 d² = 3.4327
d² = 3.4327 / 365
= .0094
d = .097 m
= 9.7 cm
If friction increases , loss of energy increases . so to achieve same kinetic energy , d will have to be increased so that initial energy increases so compensate increased loss .
the electric force decreases because the distance has an indirect relationship to the force
Explanation:
The electric force between two objects is given by

where
k is the Coulomb's constant
q1 and q2 are the charges of the two objects
r is the distance between the two objects
As we can see from the formula, the magnitude of the force is inversely proportional to the square of the distance: so, when the distance between the object increases, the magnitude of the force decreases.