All categories

3 years ago

It requires 2,500 joules to raise a certain amount of water (c = 4.186 J/g C) from 20 C to 60 C

Physics

1 answer:

Ksivusya [100]3 years ago

7 0

The mass of the water is 14.9 g

Explanation:

When a certain amount of a susbtance is heated, the temperature of the substance increases according to the equation

$Q=mC_s \Delta T$

where

Q is the amount of energy supplied to the substance

m is the mass of the substance

$C_s$ is its specific heat capacity

$\Delta T$ is the change in temperature

In this problem, we have:

Q = 2500 J of energy supplied to the water

$C_s = 4.186 J/gC$ is the specific heat capacity of water

$\Delta T=60 C - 20 C = 40^{\circ}C$ is the change in temperature of the water

Therefore we can solve for m to find the mass of the water:

$m=\frac{Q}{C_s \Delta T}=\frac{2500}{(4.186)(40)}=14.9 g$

Learn more about specific heat capacity:

brainly.com/question/3032746

brainly.com/question/4759369

#LearnwithBrainly

You might be interested in

A child is riding a merry-go-round that has an instantaneous angular speed of 1.25 rad/s and an angular acceleration of 0.745 ra

skelet666 [1.2K]

Answer:

So the acceleration of the child will be $8.05m/sec^2$

Explanation:

We have given angular speed of the child $\omega =1.25rad/sec$

Radius r = 4.65 m

Angular acceleration $\alpha =0.745rad/sec^2$

We know that linear velocity is given by $v=\omega r=1.25\times 4.65=5.815m/sec$

We know that radial acceleration is given by $a=\frac{v^2}{r}=\frac{5.815^2}{4.65}=7.2718m/sec^2$

Tangential acceleration is given by

$a_t=\alpha r=0.745\times 4.65=3.464m/sec^$

So total acceleration will be $a=\sqrt{7.2718^2+3.464^2}=8.05m/sec^2$

7 0

2 years ago

When Bob needs to send Alice a message with a digital signature, whose private key is used to encrypt the hash?

nadya68 [22]

Answer: Bob's private key

Explanation:

Since Bob is sending Alice the message, it simply implies he must have encrypted it with his key that Alice can be able to use to decrypt the message.

3 0

2 years ago

A 3.00-kg ball swings rapidly in a complete vertical circle of radius 2.00 m by a light string that is fixed at one end. The bal

Hoochie [10]

Answer:

The ball moves from lowest to highest point:

W = M g h = 3 * 9.8 * 4 = 118 J

This is work done "against" gravity so work done by gravity is -118 J

The tension of the string does no work because the tension does not

move thru any distance W = T * x = 0 because the length of the string is fixed.

5 0

2 years ago

An astronaut in a spacesuit has a mass of 100 kilograms. What is the weight of this astronaut on the surface of the Moon where t

arlik [135]

Weight = (mass) x (gravity) = (100 kg) x (1.62 m/s^2) = 162 newtons.

3 0

2 years ago

Two glass marbles (1 and 2), each supported by a nylon thread, are rubbed against a piece of silk and then are placed near a thi

iragen [17]

Answer:

d.) Marbles 1 and 2 repel each other, but no interaction occurs with marble

Explanation:

Rubbing the glass against the silk charges the glass positively.

Assuming polarization is ignored,

●Glass won't conduct electrical charge. Therefore, acting as a insulator.

●neutral objects won't distribute it's charge when affected by charge objects in proximity. Therefore, over the marble surface, the charge remain spherically symmetrical (undisturbed)

Marble 1 is positive

Marble 2 is positive

Since marble 1 and 2 are positive, repulsion will occur.

marble 3 is neutral (still assuming polarization is ignored), therefore, no interaction with marble 1 and 2

D is the answer.

4 0

3 years ago