Speed is distance over time, learn that formula and look at the image
Answer:
Opposite to the direction that you are pulling
Explanation:
Static friction acts in the opposite direction to the acceleration.
Kinetic friction acts in the opposite direction to the velocity.
Answer:
The K.E is maximum when the child is at the vertical position and the P.E is maximum at the extreme deviated position from the vertical.
Explanation:
- A child is swinging on swing up and down has both kinetic and potential energy.
- The total mechanical energy of the system is conserved throughout the system. At any instant the total mechanical energy is given by,
E = K.E + P.E
- The K.E is maximum when the child is at the vertical position.
- The P.E is maximum at the extreme deviated position from the vertical.
- And when K.E is maximum P.E becomes minimum and vice versa as per the law of conservation of energy.
Answer:
Explanation:
Expression for times period of a satellite can be given as follows
Time period T = 1.8 x 60 x 60
= 6480
T² = 
where T is time period , r is radius of orbit , G is gravitational constant and M is mass of the satellite.
6480² = 4 x 3.14² x 7.5³ x 10¹⁸ / GM
GM = 4 x 3.14² x 7.5³ x 10¹⁸ / 6480²
= 3.96 X 10¹⁴
Expression for acceleration due to gravity
g = GM / R² where R is radius of satellite
20 = 3.96 X 10¹⁴ / R²
R² = 3.96 X 10¹⁴ / 20
= 1.98 x 10¹³ m
R= 4.45 x 10⁶ m
Answer:
F=12.5N
Explanation:
Net force = rate of change of momentum
so find the change of momentum P
Pdown
Pup
dP = change in P
so
