Answer:
Force = Mass x Acceleration
Explanation:
When we swim we apply force and push the water backward with the help of our hands. In response, The water pushes us forward with an equal force. Thus, in order to move forward and swim, the swimmer lushes the water backward. Newton's 3rd law of motion
Answer:
Speed of wind = 50mi/hr, Speed of plane in still air = 400mi/hr
Explanation:
Let the speed of the wind = Vw,
Speed of the plane in still air = Vsa,
The first trip the average speed of the plane = 1575mi/4.5hours = 350mi/hr
The coming trip the wind behind = 1575mi/3.5hrs = 450
Write the motion in equation form
First trip ( the plane flew into the wind)
Vaverage = Vsa - Vw
350 = Vsa - Vw
Second trip the wind was behind
450 = Vsa +Vw
Adding the two equation
800 = 2Vas
Vas = 800/2 = 400mi/hr
Substitute for Vas into equation 1
350mi/hr = 400mi/hr - Vw
Vw = 400-350 = 50mi/hr
Answer:
The velocity of the astronaut is, v = - 0.36 m/s
Explanation:
Given data,
The mass of the astronaut, M = 84 kg
The mass of the gas expelled by the thruster, m = 35 g
= 0.035 g
The velocity of the gas expelled, v = 875 m/s
According to the conservation of momentum,
MV + mv = 0
V = - mv / M
Substituting the values,
V = - 0.035 x 875 / 84
= - 0.36 m/s
The negative sign in the velocity indicates the astronaut moves opposite to the direction of velocity of gas.
Hence, the velocity of the astronaut is, v = - 0.36 m/s
