Answer:
the jumper's speed just as he leaves the ground = 4.2 m/s
the force he must exert on the ground to perform the 0.90 m jump = 4.99 × 10³ N
Explanation:
Given that :
height h = 0.90 m
mass = 51 kg
distance s = 0.10 m
What is the jumper's speed just as he leaves the ground?
The velocity P.E = K.E
where;
g = 9.8
v = 4.2 m/s
the jumper's speed just as he leaves the ground = 4.2 m/s
What force must he exert on the ground to perform the 0.90 m jump?
Let's first determine the acceleration by using the equation of motion;
v² = u² + 2as
4.2² = 0 + 2(a)(0.10)
17.64 = 0.2 a
a = 17.64/0.2
a = 88.2 m/s²
The force F is now calculated by the relation:
F - mg = ma
F = mg+ ma
F = m(g+a)
F = 51(9.8 + 88.2)
F = 4988 N
F = 4.99 × 10³ N
Answer:
The answer is D.
Explanation:
The Law of Conservation of mass states that matter is not created nor destroyed in a chemical reaction.
Answer:
gravity
Explanation:
Gravity pulls the planets toward the Sun. Gravity pulls the moon toward Earth. Gravity pulls us toward the Earth. Gravity is a force. Inertia.
Answer:
the velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward
Explanation:
Is this exercise in kinematics
v = v₀ - g t
where g is the acceleration of the ball, which is created by the attraction of the ball to the Earth.
At the highest point
velocity must be zero.
The acceleration depends on the Earth therefore it is constant at this point and with a downward direction.
The force of the earth on the ball is towards the center of the Earth, that is, down
all other alternatives are wrong
Answer:
a) E = 7.57 10⁻⁵ N / C, b) B= 2.11 10⁻¹⁸ T, c) the magnitudes remain the same, but the sign of the responses change
Explanation:
a) The electric field due to a charged particle is
E = k q / r²
Let's look for the distance from the origin where the particle is to the point of interest
r² = (-3 10⁻³ -0)² + (-3 10⁻³ -0)²
r² = 19 10⁻⁶
The proton charge is
q = +1.6 10⁻¹⁹ C
Let's calculate
E = 8,988 10⁹ 1.6 10⁻¹⁹ / 19 10⁻⁶
E = 7.57 10⁻⁵ N / C
b) to calculate the magnetic field let's use the Biot-Savat law
B = μ₀/4π I / r²
The current is defined as the number of carriers per unit of time at a given point
I = q v
Let's calculate
B = 4π 10⁻⁷ /4π (1.6 10⁻¹⁹ 4 10⁴) / 19 10⁻⁶
B= 2.11 10⁻¹⁸ T
c) an electron has a charge of the same magnitude, but in the opposite direction, negative.
Therefore the magnitudes remain the same, but the senses (sign) of the responses change