Answer:
4th answer
Explanation:
The gradient of a distance-time graph gives the speed.
gradient = distance / time = speed
Here, the gradient is a constant till 30s. So it has travelled at a constant speed. It means it had not accelarated till 30s. and has stopped moving at 30s.
-- find the horizontal and vertical components of F1.
-- find the horizontal and vertical components of F2.
-- find the horizontal and vertical components of F3.
-- add up the 3 horizontal components; their sum is the horizontal component of the resultant.
-- add up the 3 vertical components; their sum is the vertical component of the resultant.
-- the magnitude of the resultant is the square root of (vertical component^2 + horizontal component^2)
-- the direction of the resultant is the angle whose tangent is (vertical component/horizontal component), starting from the positive x-direction.
Answer:
The answer is A
Explanation:
When a rockets thrusters push on the ground the ground pushes back on the rocket with equal force in the opposite direction. Hence the rocket takes off.
Newtons third law of motion states, for every action there is an equal and opposite reaction.
Answer:
η = 40 %
Explanation:
Given that
Qa ,Heat addition= 1000 J
Qr,Heat rejection= 600 J
Work done ,W= 400 J
We know that ,efficiency of a engine given as
Now by putting the values in the above equation ,then we get
η = 0.4
The efficiency in percentage is given as
η = 0.4 x 100 %
η = 40 %
Therefore the answer will be 40%.
The answer is b
300,000 km
