Answer:
1 second
Explanation:
h = −16t² + 32t
When, h = 16
16 = −16t² + 32t
Divide each of the numbers by 16
1 = -1t² + 2t
Rearrange the equation
1t²-2t+1 = 0
Solving by the quadratic formula, we get

So, time taken by the dolphin to jump out of the water and touch the trainer's hand is 1 second.
44.64m
Explanation:
Given parameters:
Mass of the car = 1500kg
Initial velocity = 25m/s
Frictional force = 10500N
Unknown:
Distance moved by the car after brake is applied = ?
Solution:
The frictional force is a force that opposes motion of a body.
To solve this problem, we need to find the acceleration of the car. After this, we apply the appropriate motion equation to solve the problem.
-Frictional force = m x a
the negative sign is because the frictional force is in the opposite direction
m is the mass of the car
a is the acceleration of the car
a =
=
= -7m/s²
Now using;
V² = U² + 2as
V is the final velocity
U is the initial velocity
a is the acceleration
s is the distance moved
0² = 25² + 2 x 7 x s
0 = 625 - 14s
-625 = -14s
s = 44.64m
learn more:
Velocity problems brainly.com/question/10932946
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Answer:
For the complete question provided in explanation, if the elevator moves upward, then the apparent weight will be 1035 N. While for downward motion the apparent weight will be 435 N.
Explanation:
The question is incomplete. The complete question contains a velocity graph provided in the attachment. This is the velocity graph for an elevator having a passenger of 75 kg.
From the slope of graph it is clear that acceleration at t = 1 sec is given as:
Acceleration = a = (4-0)m/s / (1-0)s = 4 m/s^2
Now, there are two cases:
1- Elevator moving up
2- Elevator moving down
For upward motion:
Apparent Weight = m(g + a)
Apparent Weight = (75 kg)(9.8 + 4)m/s^2
<u>Apparent Weight = 1035 N</u>
For downward motion:
Apparent Weight = m(g - a)
Apparent Weight = (75 kg)(9.8 - 4)m/s^2
<u>Apparent Weight = 435 N</u>
Answer:
13.78 mT
Explanation:
The peak voltage ε = ωNAB where ω = angular speed of coil = 1500 rpm = 1500 × 2π/60 rad/s = 50π rad/s = 157.08 rad/s, N = number of turns of coil = 250, A = area of coil = πr² where r = radius of coil = 10 cm = 0.10 m,
A = π(0.1 m)² = 0.03142 m² and B = magnetic field strength
So,
B = ε/ωNA
substituting the values of the variables into the equation given that ε = 17 V
So, B = ε/ωNA
B = 17 V/(157.08 rad/s × 250 turns × 0.03142 m²)
B = 17 V/(1233.8634 rad-turns-m²/s)
B = 0.01378 T
B = 13.78 mT