Answer:Due to change in direction
Explanation:
Given
Initially train has traveled a 100 km in North and after exchanging some railroad cars, it traveled 100 in south.
The velocity of the train changes as it direction of motion changes. Velocity is the vector quantity which require direction and magnitude for its reperesentation.
Answer:
you must throw 3 snowballs
Explanation:
We can solve this exercise using the concepts of conservation of the moment, let's define the system as formed by the refrigerator and all the snowballs. Let's write the moment
Initial. Before bumping that refrigerator
p₀ = n m v₀
Where n is the snowball number
Final. When the refrigerator moves
pf = (n m + M) v
The moment is preserved because the forces during the crash are internal
n m v₀ = (n m + M) v
n m (v₀ - v) = M v
n = M/m v/(vo-v)
Let's look for the initial velocity of the balls, suppose the person throws them with the maximum force if it slides in the snow (F = 100N), let's use the second law and Newton
F = m a
a = F / m
The distance the ball travels from zero speed to maximum speed is the extension of the arm (x = 1 m), let's look kinematically for the speed of the balls when leaving the arm
v₁² = v₀² + 2 a x
v₁² = 0+ 2 (100/1) 1
v₁ = 14.14 m / s
This is the initial speed for the crash
v₀ = v = 14.14 m / s
Let's calculate
n = M/m v/ (v₀-v)
n = 10/1 3 / (14.14 -3)
n = 2.7 balls
you must throw 3 snowballs
Answer:
Explanation:
The acceleration of the ball would be due to the downward force of gravity, 9.8m/s^2. In order to find the displacement given that interval of time, you have to use the corresponding kinematic formula:
The initial velocity was given, the time was given, and the acceleration was given. Therefore:
To find the required time given a desired final velocity, we can use:
Explanation:
a) The rope obeys Hooke's law, so:
F = k Δx
The elastic energy in the rope is:
EE = ½ k Δx²
Or, in terms of F:
EE = ½ F Δx
Use trigonometry to find the stretched length.
cos 20° = 35 / x
x = 37.25
So the displacement is:
Δx = 37.25 − 24
Δx = 13.25
The elastic energy per rope is:
EE = ½ (3.7×10⁴ N) (13.25 m)
EE = 245,000 J
There's two ropes, so the total energy is:
2EE = 490,000 J
Rounded to one significant figure, the elastic energy is 5×10⁵ J.
b) The elastic energy in the ropes is converted to gravitational energy.
EE = PE = mgh
5×10⁵ J = (1.2×10³ kg) (9.8 m/s²) h
h = 42 m
Rounded to one significant figure, the height is 40 m. So the claim is not justified.
Answer:
a=1.94 ms−2. is acceleration of the train
