Currently unavailable: for regular students

Degree: Materials Science (Masters) - Oxford, The Queen's College University

MyTutor guarantee

Hi, I'm Henry, a 20 year old Materials Science student at Oxford University, going into my third year. My degree is essentially uses a lot of physics and some chemistry to observe how materials (mainly metals) behave and why. Besides that, I play quite a bit of football, and cricket when it's hot and sunny.

For my sessions, I would set the student questions in advance, before going through them in the tutorial. I can explain concepts well, and from multiple angles. Understanding concepts is the most important part to learning maths and will be strived for. Practice  is key for exams, as it builds experience used to recognise patterns and similarities between questions, and eventually leads to these entering long-term memory.

#### Subjects offered

SubjectQualificationPrices
Further Mathematics A Level £20 /hr
Maths A Level £20 /hr
Further Mathematics GCSE £18 /hr
Maths GCSE £18 /hr
Maths 13 Plus £18 /hr
Maths 11 Plus £18 /hr

#### Qualifications

MathsA-levelA2A*
Further MathsA-levelA2A*
PhysicsA-levelA2A*
ChemistryA-levelA2A*
 CRB/DBS Standard ✓ 02/12/2015 CRB/DBS Enhanced No

#### General Availability

Currently unavailable: for regular students

Weeks availability
MonTueWedThuFriSatSun
Weeks availability
Before 12pm12pm - 5pmAfter 5pm
MONDAY
TUESDAY
WEDNESDAY
THURSDAY
FRIDAY
SATURDAY
SUNDAY

Please get in touch for more detailed availability

### The radius of a circular disc is increasing at a constant rate of 0.003cm/s. Find the rate at which the area is increasing when the radius is 20cm.

The rate at which the area is increasing, dA/dt, can be written with terms we know or can find out easily: dA/dt=dA/dr x dr/dt. Area of a disc, A = (pi)r^2 dA/dr=2(pi)r Rate of change of radius, dr/dt=0.003cm/s Therefore, dA/dt=2(pi)r x 0.003 = 2(pi) x 20 x 0.003 =0.12(pi) = 0.377cm^2/s

The rate at which the area is increasing, dA/dt, can be written with terms we know or can find out easily: dA/dt=dA/dr x dr/dt.

Area of a disc, A = (pi)r^2

dA/dr=2(pi)r

Rate of change of radius, dr/dt=0.003cm/s

Therefore, dA/dt=2(pi)r x 0.003

= 2(pi) x 20 x 0.003

=0.12(pi)

= 0.377cm^2/s

see more

1 year ago

972 views
Send a message

All contact details will be kept confidential.

To give you a few options, we can ask three similar tutors to get in touch. More info.

Still comparing tutors?

How do we connect with a tutor?

Where are they based?

How much does tuition cost?

How do tutorials work?

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this.