If someone is moving at a constant speed of 100 km/h and accelerate to 120km /h in 10 s what is the acceleration

А masd Of 500kg a raised to a height of 6m In 30s Find (a) Workdone .

Mazyrski [523]

Answer:

Work done is 882000joule.

power is 29400watt.

Explanation:

given,

Mass(m)=500kg

Acceleration due to gravity(g)=9.8m/s²

Height(h)=6m

Time taken(t)=30s

Workdone=?

Power=?

now,

workdone=force*displaxement

= m*g*h

=500*9.8*6

=8,82,000joule

so, the work done by the man is 8,82,000joule.

then,

power=workdone/time taken

=8,82,000/30

=29,400watt

so, the required power to lift a load is 29,400watt.

5 0

3 years ago

A girl throws a tennis ball upward with an initial velocity of 4 m/s. What is the maximum displacement of the ball?

Jobisdone [24]

Answer:

0.82 m

Explanation:

The ball is in free fall - uniform accelerated motion with constant acceleration downward, $a=g=-9.8 m/s^2$ (acceleration of gravity). So we can use the following suvat equation to solve the problem:

$v^2-u^2=2as$

where

v is the final velocity

u = 4 m/s is the initial velocity

a is the acceleration

s is the displacement

At the maximum displacement, v = 0 (the velocity becomes zero). Substituting and solving for s, we find:

$s=-\frac{u^2}{2a}=-\frac{4^2}{2(-9.8)}=0.82 m$

8 0

3 years ago

When a crown of mass 14.7 kg is submerged in water, an accurate scale reads only 13.4 kg. What material is the crown made of?

Bogdan [553]

Answer:

ρ = 1.13 10⁴ km/m³

Explanation:

For this exercise we use Newton's equilibrium equation

B –W + W_scale = 0

Where B is the thrust and W_scale is the balance reading

The push is given by Archimedes' law

B = ρ_water g V

B = W- W_scale

B = m g - m_scale g

Let's calculate

B = 14.7 9.8 - 13.4 9.8

B = 12.74 N

ρ_water g V = 12.74

V = 12.74 / ρ_water g

V = 12.74 / 1000 9.8

V = 0.0013 m³

Let's use density

ρ = m / V

We replace

ρ = 14.7 / 0.0013

ρ = 1.13 10⁴ km/m³

3 0

3 years ago

A solenoid coil with 22 turns of wire is wound tightly around another coil with 340 turns. The inner solenoid is 25.0 cm long an

LUCKY_DIMON [66]

Answer:

a) 1.34*10^-8 W

b) 1.18*10^-5 H

c) 20mV

Explanation:

a) To find the average magnetic flux trough the inner solenoid you the following formula:

$\Phi_B=BA=\mu_oNIA$

mu_o: magnetic permeability of vacuum = 4pi*10^-7 T/A

N: turns of the solenoid = 340

I: current of the inner solenoid = 0.100A

A: area of the inner solenoid = pi*r^2

r: radius of the inner solenoid = 2.00cm/2=1.00cm=10^-2m

You calculate the area and then replace the values of N, I, mu_o and A to find the magnetic flux:

$A=\pi(10^{-2}m)^2=3.141510^{-4}m^2\\\Phi_B=(4\pi*10^{-7}T/A)(340)(0.100A)(3.1415*10^{-4}m^2)=1.34*10^{-8}W\\$

the magnetic flux is 1.34*10^{-8}W

b) the mutual inductance is given by:

$M=\mu_o N_1 N_2 \frac{A_2}{l}$

N1: turns of the outer solenoid = 22

N2: turns of the inner solenoid

A_2: area of the inner solenoid

l: length of the solenoids = 25.0cm=0.25m

by replacing all these values you obtain:

$M=(4\pi*10^{-7}T/A)(340)(22)\frac{3.14*10^{-4}m^2}{0.25m}=1.18*10^{-5}H$

the mutual inductance is 1.18*10^{-5}H

c) the emf induced can be computed by using the mutual inductance and the change in the current of the inner solenoid:

$\epsilon_1=M\frac{dI_2}{dt}$

by replacing you obtain:

$\epsilon_1=(1.18*10^{-5}H)(1700A/s)=0.02V=20mV$

the emf is 20mV

7 0

3 years ago

Read 2 more answers

PLEASE HELPPPPP

Ganezh [65]

The only graph that accurately depict the given motion is graph D.

The given parameters;

initial position of the man = 0

direction of the man's first displacement = backward
time of first motion, t₁ = 6 seconds
velocity of this first displacement = v₁
time without any motion (zero movement) = 6 seconds
direction of the second displacement = forward
velocity of second displacement = 2v₁

Let the acceleration of the first displacement = a

Acceleration of the second displacement = 2a

From the given graphs we can eliminate every graph without initial decrease or motion towards the negative direction.

The only options with initial motion towards the negative direction are;

graph B, and

graph D.

The difference between graph B and D;

in graph B there is a uniform motion for 6 seconds

in graph D there is no motion for 6 seconds (this is obvious as the line fall directly on top of the horizontal axis maintaining a value of zero for 6 seconds).

Thus, the only graph that accurately depict the given motion is graph D.

Learn more here: brainly.com/question/21095906

5 0

2 years ago